The majority of photons in the x-ray beam are created through the process of:

The process through which the majority of photons in the x-ray beam are created is Bremsstrahlung radiation. This occurs when high-speed electrons are suddenly decelerated upon interacting with the nucleus of a target atom, typically tungsten, in the x-ray tube. As these electrons collide with the nucleus, they lose energy and emit energy in the form of x-ray photons.

Bremsstrahlung, which translates to "braking radiation," contributes significantly to the x-ray output because this process can generate a wide spectrum of photon energies. In fact, it accounts for about 70-90% of the total x-ray production in a standard x-ray machine. The broad range of energies produced by Bremsstrahlung makes it critical for creating the diverse x-ray spectra necessary for effective imaging.

In contrast, characteristic radiation, another process mentioned in the options, occurs when an electron from the inner shell of an atom is ejected and an outer shell electron falls into the vacancy, releasing a photon with a discrete energy characteristic of the element. This process contributes less to the overall x-ray beam compared to Bremsstrahlung.

Nuclear fusion and radioactive decay are not involved in the production of x-ray photons in this context. Nuclear fusion combines atomic nuclei